How to get clients for photoshoots without losing them?

I'm a photo hobbyist but I would do it for money whenever I get the opportunity. Sometimes people see me with a camera (Nikon DSLR) and they ask if I have a card. I don't really like carrying cards so I give them my number and they say they will call me but I never get any calls. What could I do to be more successful?

How to get clients for photo shoots without losing them?
Yeah I know how that feels. Those photo shoots just like to run away and get lost, leaving your clients standing there.

Get cards. But it doesn't matter what business you are in, for every 100 cards you give out you may get 2 calls. That's why they are so cheap.

Business name.
Build a portfolio.
Get a website with your photos online.
Buy cards.
Pass out cards.

Nobody will respond if you just give them a number. You have to give them a card. Something that they can hold on to and refer back to.

You already know the answer. People are asking for your card - so at least have a card ready to give them. You only need to carry 3 with you at any time.